As the astute reader may notice, however, this flavor of updating scheme does not work in curved space-time where the notion of a globally conserved energy is not generally available. Thus it is desirable to pursue a more robust criterion for updating that survives, even when energy conservation as an updating principle does not. One such alternative strategy is to pursue a criterion for updating that is founded on geometric principles. For instance, in [1]}, A. Caticha models the e-phase space as a cotangent bundle, which comes naturally equipped with a symplectic structure and thus all the usual accoutrements of the canonical framework, including Hamiltonian generators, Poisson brackets, etc. However, while such an approach provides an interesting way forward in ED, there are still some lingering issues needing to be resolved; not least of which is whether the cotangent bundle is a geometric structure that is rich enough to model all physically relevant quantum states (see e.g., [2]}).
